I've been using this for years at work, and thanks to MT, I now have a deeper understanding of exactly why/how it helps make my O3's more effective.
It's called the "heart/tree/star" model.
The "[b]heart[/b]" represents what the employee truly loves to work on.
The "[b]tree[/b]" represents how the employee wants to grow in their career.
The "[b]star[/b]" represents how they prefer to be rewarded.
If you can answer these 3 questions about your employee, you can help them find projects they're going to be passionate about his/her work, (and a passionate employee can be a productive employee!) you're going to understand their career goals and can help find them projects to reach those goals, and you're going to know the most & least effective ways to reward them.
It occurred to me while re-listening to the one-on-one podcast that there are elements of DISC in here as well as just having an effective relationship with your employee.